Income Tax form 17

HMRC Form 17 is a UK tax form used by married couples or civil partners who own property together and want to be taxed on the actual split of income rather than the default 50:50 split.  

By default, HMRC assumes that income from jointly owned property (like rental income or savings interest) owned by spouses/civil partners is split 50:50, regardless of who actually owns what. Form 17 lets you override this, so the income is taxed according to your true beneficial ownership (e.g. 90% / 10%).

When you would use Form 17

You use Form 17 if all of the following apply:

• You are married or in a civil partnership
• You own property or assets jointly
• The beneficial ownership is not 50:50
• You want HMRC to tax the income according to that unequal split

Common example:

• One spouse owns 99% of a rental property
• The other owns 1%
• Without Form 17, HMRC taxes rental income 50:50
• With Form 17, income is taxed 99/1

What assets it applies to

Form 17 can apply to income from:

• Rental property
• Bank or building society accounts
• Shares or investments
   

❌ It does not apply to:

• Salary or business income
• Assets owned by unmarried couples
• Assets owned solely by one spouse

 You must have evidence
A Declaration of Trust or similar legal document showing the unequal ownership.
Time limit
Form 17 must be submitted within 60 days of signing the ownership document.
Both spouses must sign the declaration of trust.
Applies going forward only. You cannot backdate it.
 

If any of these are missing, HMRC will reject it.

• HMRC will tax each spouse in line with their ownership share
• Often used for tax efficiency, e.g. shifting income to a lower-rate taxpayer
• Capital Gains Tax on sale usually follows the same ownership split

Simple example

• Rental income: £20,000 per year
• Ownership: Spouse A 90%, Spouse B 10%
• Taxed income:
  • A: £18,000
  • B: £2,00 

Without Form 17:

Each would be taxed on £10,000

• Submitting Form 17 without a declaration of trust  
• Missing the 60-day deadline 
• Assuming it changes ownership (it doesn’t – it only reports it)  
• Thinking it applies to unmarried couples

Form 17 = tell HMRC the real ownership split for income taxIt’s a powerful but strictly policed form, so the paperwork and timing must be right.If you want, I can:

• Check whether Form 17 applies to your situation  
• Explain how to set up a declaration of trust  
• Walk through a real example using your numbers